Sensor or combined sensor-munition field units (xe2x80x9cfield unitsxe2x80x9d), such as wide area munitions, are commonly distributed across a predefined region of a defensive position. Such units are deployed according to a number of techniques, including scattering from an air position, dropping from a moving truck, or hand-placement by installation personnel. Upon deployment, a field unit is required to right itself so that sensors can begin to sweep for threats or targets of interest.
A field unit may include a large upper body, e.g., in the shape of a canister, that is suspended above a lower base. The base may include various mechanisms for rotating and positioning the upper body. A plurality of feet or legs are typically released from the base for righting and stabilizing the unit. The upper body houses various systems which may include, for example, a munition or plurality of submunitions, antennae, seismic sensors, acoustic sensors, optic sensors, radar sensors, and the like.
Upon determination of a threat or target of interest, the base mechanism causes the upper body to cant or incline at a pre-defined angle and to rotate in order to orient the associated sensors or munitions in the general direction of the threat. Accordingly, additional data can be collected on the target, and, if desired, a munition launched in that direction.
In conventional field units, the upper body rotates relative to the base at fixed, indexed increments, for example at 9 degree increments, using complicated mechanical systems. In addition, the angle of the inclination is also fixed, for example, to a 45 degree inclination angle. Such units rely primarily on mechanical systems for righting and rotational positioning. They include for example, large-load springs that are used to deploy the feet for righting the unit. While such springs are the most reliable springs available, they tend to be single-use springs and are therefore expensive. In addition, they are difficult to replace and service, and in fact are dangerous for installation personnel, since untimely activation can result in severe injury.
In addition, the rotation mechanism, being fixed at 9 degree indexed increments, does not afford a high degree of precision that might otherwise be desired in modern tracking systems. This applies as well to the fixed 45 degree inclination angle of the upper body. Fixed inclination and rotation angles tend to limit the functionality and effectiveness of these units.
The present invention is directed to a system and method that address the limitations of the conventional approaches. In particular, the present invention provides a system by which a deployed field unit provides for a continuous range of rotation of the upper body and a continuous range of cant or inclination angle in the upper body relative to the lower base. An optional system for deploying the legs provides for continuous, controlled motion in their release. In doing so, the present invention provides a system with a higher degree of flexibility, precision and reliability.
In one aspect, the present invention is directed to a system for controlling the inclination angle and rotation angle of a body. A rotary actuator is coupled to a base. A pivot actuator is coupled to an output shaft of the rotary actuator. The rotary actuator controls the angular position of the pivot actuator. A displacement member is coupled to an output shaft of the pivot actuator. The pivot actuator controls the linear position of the displacement member. A support shaft is pivotably coupled to the displacement member. A bearing, for example a spherical bearing, includes a fixed portion that is coupled to the base and a moving portion that is coupled to the support shaft. In this manner, the angular position and linear position of the displacement member is translated to a corresponding rotation angle and inclination angle in the support shaft.
In one embodiment, the support shaft extends from the displacement member through the bearing. The bearing may comprise, for example, a spherical bearing, in which case, the fixed portion comprises a socket and the moving portion comprises a ball. A body, for example, comprising a munition, a plurality of submunitions, antenna, seismic sensor, acoustic sensor or optic sensor is coupled to the support shaft.
In another embodiment, the rotary actuator comprises a stepper motor. A platform is coupled to the output shaft of the rotary actuator, and the pivot actuator is coupled to the platform. The pivot actuator may comprise, for example, a linear actuator. In one example, the linear actuator comprises a stepper motor that induces motion in a threaded screw, and the displacement member comprises a displacement carriage, the threaded screw communicating with a corresponding thread in the displacement carriage for inducing linear motion in the displacement carriage. The linear actuator may further comprise a rail, and the displacement carriage is slidably mounted to the rail. In another example, the linear actuator comprises a stepper motor that induces linear motion in the output shaft, the output shaft communicating with the displacement member for inducing linear motion in the displacement member.
In another embodiment, the support shaft includes a spherical bearing and the displacement member includes a socket for communicating with the spherical bearing of the support shaft. Alternatively, the support shaft may include a disk bearing. The base may further comprise a shroud for housing the base, in which case the fixed portion of the bearing is coupled to the shroud. The weight of the body is substantially supported by the shroud.
In this manner, the rotary actuator controls the angular position of the pivot actuator over a continuous range of angular positions, and the pivot actuator controls the linear position of the displacement member over a continuous range of linear positions.
In another embodiment, a plurality of legs are rotatably coupled to the body. An articulated joint network couples the legs and a motor rotates the joint network for collectively deploying the legs.
In another aspect, the present invention is directed to a system for controlling the inclination angle and rotation angle of a body. The system includes a base, a rotary actuator, a linear actuator, and a displacement member. The linear actuator controls the linear position of the displacement member and the rotary actuator controls the angular position of the displacement member. A support shaft is pivotably coupled to the displacement member. A housing is coupled to the base for housing the rotary actuator, linear actuator and displacement member. A bearing includes a fixed portion that is coupled to the housing and a moving portion that is coupled to the support shaft. In this manner, the angular position and linear position of the displacement member is translated to a corresponding rotation angle and inclination angle in the support shaft.
In another aspect, the present invention is directed to a method for controlling the inclination angle and rotation angle of a body. The angular position of a displacement member is controlled about a longitudinal axis of a base over a continuous range of angular positions. The linear position of the displacement member is controlled relative to the longitudinal axis of the base over a continuous range of linear positions. The displacement member is pivotably coupled to a support shaft of the body at a first position of the support shaft and the support shaft is pivotably coupled to the base at a second position of the support shaft. In this manner, the angular position and linear position of the displacement member is translated to a corresponding rotation angle and inclination angle in the support shaft.
In another aspect, the present invention is directed to a method for positioning a body. A support shaft is moved through a continuous range of inclination angles relative to a base. The support shaft is rotated through a continuous range of rotation angles about an axis of rotation. A body coupled to the support shaft is thereby moved to a desired rotation angle and inclination angle.